Answer:
Kc = 255
Step-by-step explanation:
Step 1: Write the balanced equation
H₂(g) + I₂(g) ⇌ 2 HI(g)
Step 2: Make an ICE chart
H₂(g) + I₂(g) ⇌ 2 HI(g)
I 3.00 2.20 0
C -x -x +2x
E 3.00-x 2.20-x 2x
Step 3: Find the value of x
The concentration at equilibrium of I₂ is 0.0800 M. Then,
2.20 - x = 0.0800
x = 2.12
Step 4: Calculate the concentrations at equilibrium
[H₂] = 3.00-x = 0.88 M
[I₂] = 0.0800 M
[HI] = 2x = 4.24 M
Step 5: Calculate the equilibrium constant (Kc)
Kc = [HI]²/[H₂]×[I₂]
Kc = 4.24²/0.88×0.0800
Kc = 255